Patent application title: GUIDE VANE ARRANGEMENT OF A TURBOMACHINE

Abstract:

A guide vane arrangement of a turbomachine includes a casing, at least one
guide vane carrier connected to the casing and having a first carrying
portion and a second carrying portion spaced apart axially from the first
carrying portion, a plurality of guide vanes connected to the guide vane
carrier and arranged next to each other in a circumferential direction,
and at least one securing element connected to the guide vane carrier and
configured to provide an axial fixing of at least one of the guide vanes.
Each guide vane has a platform including a first locking portion and a
second locking portion spaced apart axially from the first locking
portion, wherein each of the first and second locking portions and the
respective first and second carrying portion are adapted to provide an
axially pluggable and a radially positive fastening between the guide
vane carrier and the respective guide vane.

Claims:

1. A guide vane arrangement of a turbomachine, comprising:a casing;at
least one guide vane carrier connected to the casing and having a first
carrying portion and a second carrying portion spaced apart axially from
the first carrying portion;a plurality of guide vanes connected to the
guide vane carrier and arranged next to each other in a circumferential
direction, each guide vane having a platform including a first locking
portion and a second locking portion spaced apart axially from the first
locking portion, wherein each of the first and second locking portions
and the respective first and second carrying portion are configured to
provide an axially pluggable and a radially positive fastening between
the guide vane carrier and the respective guide vane; andat least one
securing element connected to the guide vane carrier and configured to
provide an axial fixing of at least one of the guide vanes.

2. The guide vane arrangement as recited in claim 1, wherein the first and
second carrying portions and the first and second locking portions extend
in the circumferential direction.

3. The guide vane arrangement as recited in claim 1, wherein the first
locking portion and the second locking portion are disposed at a mutual
radial spacing.

4. The guide vane arrangement as recited in claim 1, wherein the first
carrying portion and the second carrying portion are disposed at a mutual
radial spacing.

5. The guide vane arrangement as recited in claim 1, wherein the first
carrying portion has an inner collar projecting radially inward and
extending in the circumferential direction, the inner collar including an
inner tongue extending axially and circumferentially, andwherein the
first locking portion has an inner groove, the inner groove being axially
open and extending circumferentially, wherein the inner tongue and inner
groove are configured to provide a first tongue-and-groove connection
between the guide vane carrier and the respective guide vane.

6. The guide vane arrangement as recited in claim 1, wherein the second
locking portion has an outer collar projecting radially outward and
extending in the circumferential direction and including an outer tongue
extending axially and circumferentially,wherein the second carrying
portion includes an outer groove, the outer groove being axially open and
extending circumferentially, andwherein the outer tongue and outer groove
are configured to provide a second tongue-and-groove connection between
the guide vane carrier and the respective guide vane.

7. The guide vane arrangement as recited in claim 1, wherein at least one
of the platforms includes a cavity delimited radially inward by a base
and delimited axially and circumferentially by first and second walls
projecting radially outward from the base,wherein the guide vane carrier
has a common collecting duct extending circumferentially,wherein the
casing has at least one cooling-gas supply duct connected fluidically to
the common collecting duct, andwherein the guide vane carrier has at
least one connecting orifice connecting the common collecting duct
fluidically to the cavity.

8. The guide vane arrangement as recited in claim 7, the first locking
portion is disposed on the first wall.

9. The guide vane arrangement as recited in claim 8, the second locking
portion is disposed on the second wall.

10. The guide vane arrangement as recited in claim 7, wherein each
platform includes a cavity, each guide vane has a flow profile projecting
radially inward from the base, each flow profile containing a cooling-gas
path connected fluidically to the cavity through the base.

11. The guide vane arrangement as recited in claim 1, further comprising a
plurality of gap seal arrangements, each extending axially between
circumferentially adjacent guide vanes and configured to seal a gap
between the circumferentially adjacent guide vanes.

12. The guide vane arrangement as recited in claim 11, wherein the gap
seal arrangement has a first axial sealing plate disposed in a region of
the first locking portion and extending circumferentially and radially.

13. The guide vane arrangement as recited in claim 12, wherein the
platforms of the two circumferentially adjacent guide vanes include two
circumferentially opposite first axial sealing slits, and wherein the
first axial sealing plate is disposed in the first slits.

14. The guide vane arrangement as recited in claim 12, wherein the gap
seal arrangement has a second axial sealing plate disposed in a region of
the second locking portion and extending circumferentially and radially.

15. The guide vane arrangement as recited in claim 14, wherein the
platforms of the two circumferentially adjacent guide vanes include two
circumferentially opposite second axial sealing slits, and wherein the
second axial sealing plate is disposed in the second slits.

17. The guide vane arrangement as recited in claim 11, wherein the
platforms of the two circumferentially adjacent guide vanes include two
circumferentially opposite radial sealing slits and wherein the radial
sealing plate disposed in the radial sealing slits.

18. The guide vane arrangement as recited in claim 1, wherein the
turbomachine includes a gas turbine.

19. A turbomachine comprising at least one row of guide vanes and the
guide vane arrangement as recited in claim 1.

Description:

[0001]This application is a continuation of International Patent
Application No. PCT/EP2006/065188, filed on Aug. 9, 2006, which claims
priority to Swiss Patent Application No. CH 1348/05, filed on Aug. 17,
2005. The entire disclosure of both applications is incorporated by
reference herein. The International Patent Application designated the
United States and was published in German as WO 2007/020217 on Feb. 22,
2007.

[0002]The present invention relates to a guide vane arrangement of a
turbomachine, in particular of a gas turbine.

BACKGROUND

[0003]A typical guide vane arrangement comprises at least one guide vane
carrier which is fastened to a casing of a turbomachine. Moreover, a
guide vane arrangement of this type comprises a plurality of guide vanes
which are fastened to the guide vane carrier and are arranged next to one
another in the circumferential direction. Normally, each guide vane has a
platform possessing at least two locking portions which are spaced apart
from one another circumferentially. Each locking portion has a tongue
which projects from the platform in a circumferential direction and which
extends in the axial direction. The guide vane carrier has at least two
carrying portions which are spaced apart from one another in the
circumferential direction. Each carrying portion has a groove which is
open in the circumferential direction and which extends in the axial
direction. The tongues of the locking portions and the grooves of the
carrying portions are configured such that they provide an axially
pluggable and radially positive fastening between the guide vane carrier
and the respective guide vane. A guide vane arrangement of this type
affords the possibility of mounting and demounting individual guide
vanes, without the entire guide vane carrier being dismantled.

SUMMARY OF THE INVENTION

[0004]An object of the present invention is to provide an improved guide
vane arrangement which preserves the possibility of the simple mounting
and demounting of individual guide vanes.

[0005]One aspect of the present invention is the idea of arranging the
locking portions and the complementary carrying portions with an axial
offset. The mounting and demounting of the guide vanes are simplified,
since the axial movement of the guide vanes which has to be carried out
so that the positive fastening can be made is reduced significantly.
Problems, such as distortion, jamming and tilting along the axial
contact, are reduced. Since the cooperating carrying portions and locking
portions extend in the circumferential direction, the guide vane
arrangement according to the invention makes it possible to adjust the
guide vanes in the circumferential direction.

[0006]According to a preferred embodiment, the platform has a cavity which
is delimited radially on the inside by a base and which is delimited
axially and circumferentially by walls which project outward from the
base. The guide vane carrier has a common collecting duct which extends
in the circumferential direction. The casing has at least one cooling-gas
supply duct which is connected fluidically to the common collecting duct.
The guide vane carrier has a plurality of connecting orifices which in
each case connect the common collecting duct fluidically to one of the
cavities. By virtue of this feature, the guide vane carrier comprises an
important component of a cooling-gas supply path. Said common collecting
duct significantly simplifies the supply of cooling gas through the
casing of the turbomachine, since the cooling-gas supply duct in the
casing can be arranged in a suitable portion of the casing, and because
the arrangement of the cooling-gas supply duct is independent of the
arrangement of the guide vanes.

[0007]In another embodiment of the invention, the guide vane arrangement
makes it possible to equip circumferentially adjacent guide vanes with a
gap seal arrangement. Said gap seal arrangement is designed for sealing a
gap which extends axially in each case between two circumferentially
adjacent guide vanes. With the aid of a gap seal arrangement of this
type, the leakage of cooling gas through said gap can be reduced
significantly. A decrease in the leakage of cooling gas results in an
increase in the efficiency of the turbomachine.

[0008]Other objects and many of the concomitant advantages of the present
invention are perceived more easily and are better understood by
reference to the following detailed description, insofar as this is taken
into account in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]Preferred embodiments of the invention are illustrated in the
drawings and are explained in more detail in the following description.
Features which are essentially or functionally identical or similar are
referred to by the same reference symbol or reference symbols.

[0010]FIG. 1 shows a simplified diagrammatic axial section through a guide
vane arrangement corresponding to an embodiment of the invention,

[0011]FIG. 2 shows a view of a detail according to the arrow II in FIG. 1,

[0012]FIG. 3 shows a circumferential section corresponding to the
sectional lines III in FIG. 1, and

[0013]FIG. 4 shows an exploded illustration of the guide vane arrangement
according to FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0014]According to FIG. 1, a guide vane arrangement 1 according to an
embodiment of the invention has at least one guide vane carrier 2 and a
plurality of guide vanes 3. The guide vane arrangement 1 is part of a
turbomachine 4. Said turbomachine 4 is, in particular, a gas turbine. In
principle, the turbomachine may also be a steam turbine or a compressor.
The guide vane arrangement 1 has the guide vanes 3 of a guide vane row of
the turbomachine 4. Conventionally, the turbomachine 4 is equipped with a
plurality of guide vane rows.

[0015]In principle, each of these guide vane rows may have the guide vane
arrangement 1 according to the invention.

[0016]The guide vane carrier 2 is fastened to a casing 5 of the
turbomachine 4. The guide vanes 3 are fastened to the guide vane carrier
2. In order to form the guide vane row, the guide vanes 3 are arranged
next to one another in the circumferential direction.

[0017]Each guide vane 3 has a platform 6 and a flow profile 7 which
projects radially and inward from the platform 6. The platform 6 has a
first locking portion 8, which is illustrated on the left side of FIG. 1,
and a second locking portion 9, which is illustrated on the right side of
FIG. 1. The locking portions 8, 9 are arranged with a mutual axial
spacing. For example, the first locking portion 8 is arranged in the
region of an outflow side 10 of the profile 7, while the second locking
portion 9 is arranged in the region of an inflow side 11 of the profile
7.

[0018]The guide vane carrier 2 has, complementarily to the locking
portions 8, 9, a first carrying portion 12 and a second carrying portion
13. The two carrying portions 12, 13 are likewise spaced apart axially
from one another. Each locking portion 8, 9 and the associated carrying
portion 12, 13 are designed such that they provide an axially pluggable
and a radially positive fastening between the guide vane carrier 2 and
the respective guide vane 3. In other words, the cooperating locking
portions 8, 9 and carrying portions 12, 13 afford an axial plugging-in or
pressing movement for mounting the respective guide vane 3 and an axial
unplugging or pulling movement for demounting said guide vane. In the
mounted state, the cooperating locking portions 8, 9 and carrying
portions 12, 13 set up a positive radial fixing between the guide vane
carrier 2 and the respective guide vane 3.

[0019]In addition, the guide vane arrangement 1 has at least one securing
element 14 which is fastened to the guide vane carrier 2. Said securing
element 14 is designed such that it provides an axial fixing of at least
one of the guide vanes 3. The guide vane 3, in its mounted state, is
axially fixed or secured by means of said securing element 14.

[0020]Preferably, the carrying portions 12, 13 and the locking portions 8,
9 extend in the circumferential direction. In principle, during mounting,
each guide vane 3 can be adjusted in the circumferential direction. Such
adjustment may be advantageous in order to eliminate or to reduce play
between adjacent guide vanes 3. According to the preferred embodiment,
the first locking portion 8 and the second locking portion 9 are arranged
at a mutual radial spacing. This features leads to an axially compact
structure of the guide vane arrangement 1. Moreover, this feature reduces
production costs. The first carrying portion 12 and the second carrying
portion 13 may, of course, also be spaced apart radially from one
another.

[0021]The first carrying portion 12 has an inner collar 15 which projects
radially inward from the guide vane carrier 2 and which extends in the
circumferential direction. Said inner collar 15 is equipped with an inner
tongue 16 which extends axially and circumferentially. Complementarily to
this, the first locking portion 8 has an inner groove 17. Said inner
groove 17 is axially open and extends circumferentially. Said inner
tongue 16 and said inner groove 17 are configured such that they provide
a first tongue-and-groove connection 18 between the guide vane carrier 2
and the respective guide vane 3. In the mounted state, the inner tongue
16 projects axially into the inner groove 17 and engages radially on the
platform 6.

[0022]The second locking portion 9 has an outer collar 19 which projects
radially outward from the platform 6 and which extends in the
circumferential direction. Said outer collar 19 is equipped with an outer
tongue 20 which extends in the axial direction and in the circumferential
direction. The second carrying portion 13 is correspondingly equipped
with an outer groove 21 which is axially open and which extends
circumferentially. Said outer tongue 20 and said outer groove 21 are
configured such that they provide a second tongue-and-groove connection
22 between the guide vane carrier 2 and the respective guide vane 3. In
the mounted state, the outer tongue 20 extends into the outer groove 21
and engages radially on the guide vane carrier 2.

[0023]As mentioned above, during mounting, the guide vane 3 can be
adjusted in the circumferential direction. In order to fix
circumferentially a set position between the guide vane carrier 2 and the
respective guide vane 3, a locking pin 23 is provided. Said locking pin
23 penetrates into a depression 24 which is cut out in the outer collar
19. Said locking pin 23 is screwed into a complementary threaded orifice
25 which is provided in the guide vane carrier 2.

[0024]According to FIG. 2, the guide vane 3 is preferably equipped with at
least one pull-out orifice 26 which is a threaded orifice provided for
cooperation with a pull-out device, not shown. A pull-out device of this
type makes it simpler to pull or pull off the guide vane 3 from the guide
vane carrier 2.

[0025]According to FIG. 3, the platform 6 has a cavity 27 which is open
toward the guide vane carrier 2. Said cavity 27 is delimited radially on
the inside by a base 28 of the platform 6. The flow profile 7 projects
radially inward from said base 28. The cavity 27 is delimited axially and
circumferentially by walls 29. Said walls 29 project radially outward
from the base 28. The cavity 27 forms a cooling-gas distribution chamber.
For example, the flow profile 7 contains a cooling-gas path 30 which is
connected fluidically to the cavity 27 by means of the base 28.

[0026]The guide vane carrier 2 is equipped with a common collecting duct
31. Said common collecting duct 31 extends circumferentially and
preferably extends along the entire guide vane carrier 2. The casing 5 is
equipped with at least one cooling-gas supply duct 32 which is connected
fluidically to a cooling-gas supply device, not shown. Moreover, said
cooling-gas supply duct 32 is connected fluidically to the common
collecting duct 31 and consequently supplies the common collecting duct
31 with cooling gas. The cooling-gas flow is symbolized by means of
arrows 33. The guide vane carrier 2 is additionally equipped with a
plurality of connecting orifices 34. Each connecting orifice 34 connects
the common collecting duct 31 fluidically to one of the cavities 27.
Correspondingly, the cavities 27 of the guide vanes 3 are supplied with
cooling gas from the common collecting duct 31 via the respective
connecting orifice 34. A baffle plate 43 may be arranged in the cavity
27.

[0027]The use of a common collecting duct 31 for supplying cooling gas,
which is preferably air or steam, to a plurality of or all of the guide
vanes 3 has the advantage that the supply of cooling gas to the
respective guide vane 3 can be provided at the same pressure on account
of approximately identical cooling-gas path configurations between the
common collecting duct 31 and the cavities 27 of the respective guide
vanes 3. In addition, the at least one cooling-gas supply duct 32 can be
arranged within the casing 5 independent of the position of the
respective guide vane 3. The number of cooling-gas supply ducts 32 may
also be smaller than the number of guide vanes 3 to be supplied with
cooling gas. Flexibility in the design of the casing 5 is increased, with
the result that the production costs for the casing 5 are reduced.

[0028]One of the walls 29, which axially delimits the cavity 27 in the
region of the outflow side 10 of the flow profile 7, is provided with the
first locking portion 8. The other wall 29, which axially delimits the
cavity 27 in the region of the inflow side 11 of the flow profile 7, is
equipped with the second locking portion 9. Correspondingly, the cavity
27 extends axially from the outflow side 10 as far as the inflow side 11.
Said cavity 27 extends in the circumferential direction over the entire
circumferential extent of the base 28.

[0029]According to FIG. 3, circumferentially adjacent guide vanes 3 are
equipped with a gap seal arrangement 35. Said gap seal arrangement 35 is
designed for sealing a gap 36 which is formed in each case between two
circumferentially adjacent guide vanes 3. Said gap 36 extends axially
between the two adjacent guide vanes 3. In particular, the gap 36 extends
between two walls 29 which circumferentially delimit the cavities 27 of
said guide vanes 3.

[0030]Said gap seal arrangement 35 has a radial sealing plate 37 which
extends circumferentially and axially. The radial sealing plate 37
possesses a relatively small thickness perpendicularly to its extent,
since the radial sealing plate 37 is shaped as a plate. The platforms 6
of the two adjacent guide vanes 3 are provided with two radial sealing
slits 38. Said pair of radial sealing slits 38 are arranged
circumferentially opposite one another and extend axially and
circumferentially. The radial sealing plate 37 is inserted into the
radial sealing slit 38 in order to achieve a radial sealing action.

[0031]According to FIG. 1, the gap seal arrangement 35 may also have a
first axial sealing plate 39 which is arranged in the region of the first
locking portion 8. Said first axial sealing plate 39 extends
circumferentially and radially. The first axial sealing plate 39
possesses a relatively small thickness perpendicularly to its extent. The
platforms 6 of the two adjacent guide vanes 3 are provided with two
circumferentially opposite first axial sealing slits 40. Said first axial
sealing slits 40 extend circumferentially and radially. The first axial
sealing plate 39 is inserted into said pair of first axial sealing slits
40 in order to achieve an axial sealing action.

[0032]In addition, the gap seal arrangement 35 also has a second axial
sealing plate 41 which extends parallel to the first axial sealing plate
39. Said second axial sealing plate 41 is arranged in the region of the
second locking portion 9. The platforms 6 of the two adjacent guide vanes
3 are likewise provided with two circumferentially opposite second axial
sealing slits 42, into which the second axial sealing plate 41 is
inserted in order to achieve an axial sealing action.

[0033]According to FIG. 4, each individual guide vane 3 can be mounted and
demounted independently of other guide vanes 3. In particular, the guide
vane carrier 2 does not have to be demounted in order to mount and
demount the guide vanes 3.

[0034]For mounting the guide vane 3 on the guide vane carrier 2, the
respective guide vane 3 is moved axially according to an arrow 44. In a
final phase of this axial movement, the two tongue-and-groove connections
18, 22 are made by the tongues 16, 20 being plugged axially into the
respective grooves 17, 21. After this plugging-in operation, the
respective guide vane 3 is fastened radially to the guide vane carrier 2
by means of the positive connection provided by the tongue-and-groove
connections 18, 22.

[0035]In order to fix the guide vane 3 circumferentially with respect to
the guide vane carrier 2, the locking pin 23 is mounted. After the
mounting of the locking pin 23, the securing element 14 is mounted on the
guide vane carrier 2. Preferably, the securing element 14 and the guide
vane carrier 2 are equipped with two tongue-and-groove connections 45
which resemble the tongue-and-groove connections 18, 22 between the guide
vane 3 and the guide vane carrier 2. The securing element 14 is fastened
to the guide vane carrier 2 by means of at least one locking bolt 46 in
conjunction with at least one inlet segment 47. Said inlet segment 24 is
equipped with an outer step 48. The platform 6 is provided with an inner
step 49 which is arranged at the rear end of the platform 6 with respect
to the mounting direction 44. In the mounted state according to FIG. 1,
the outer step 48 of the inlet segment 47 is in engagement with the inner
step 49 of the guide vane 3. The inlet segment 47 is consequently carried
by the guide vane 3. The inlet segment 47 may additionally be fastened to
the guide vane carrier 2 by further fastening means, not shown.

[0036]The locking bolt 46 penetrates through the securing element 14
within a through orifice 50 and projects into a blind hole 51 which is
formed on the guide vane carrier 2. In the mounted state, said locking
bolt 46 is carried radially on the inside by the inlet segment 47. The
locking bolt 46 is carried radially on the outside by the guide vane
carrier 2 by means of a compression spring 52. The locking bolt 46
secures the axial position of the securing element 14 and the support
between the two steps 48 and 49.